Tim Bale concedes that his work with Paul Webb and Monica Poletti on the ESRC-funded Party Members Project “can only ever be a snapshot of a moving target”; that more Labour members may be younger than their research suggests, and that “we would love to be able to compare and weight our data to the data on members held by the parties themselves, presuming of course that they hold it accurately and comprehensively, which in the Conservatives’ case is open to serious doubt. But, thus far, they have all proved rather reluctant to make it publicly available”.

Plenty of other interesting stuff here, too. Tory members are likely to be older, more white, more qualified (in terms of university degrees) more middle class and more male and more southern than Labour ones. They are also more likely to be Scots, a finding that would have been bewilderingly unlikely until very recently. And, as John Rentoul has pointed out, so much for the youthquake, at least on these figures. Twenty four per cent of Bale’s Tory respondents were between 18 and 44, four points lower than the number of his Labour respondents of the same age.